Thermal Physics Chapters 13, 14, 15 Review

Terms and Concepts to Know A measure of the average kinetic energy in a system is? Celsius temperature scale vs. Kelvin temperature scale Constant temperature? Constant pressure? Constant volume? No heat is allowed to flow into or out of the system? (Q=0) What concepts are described by: The first law of thermodynamics? The second law of thermodynamics? A measure of the flow of thermal energy through a medium is? What must be true about two given objects for energy to be transferred as heat between them? Why do orange growers spray a mist of water over there trees during the night? Compare the absorption of heat and change in temperature as energy is added to a substance changed from solid to liquid to gas. C

Problems to Solve: Ideal Gases An ideal gas is held at 300 kPa in a piston chamber. Initially the gas takes up 3.0 L of space. After being heated, it takes up 5.0 L of space. How much work is done on the gas? An ideal gas is enclosed in a flexible volume at an initial temperature and pressure. Halving the pressure and quartering the temperature has what effect on the volume? 3.14 mol of an ideal gas is trapped in a flexible sphere initally of radius 1.59 m at 265 K. The volume expands isobarically to 358 K. What is the change in volume of the gas? 4.0 mol of an ideal gas are isobarically expanded from a sphere with diameter 4.0 cm to a cube with 4.0 cm sides. If the initial temperature of the gas is 3,000 K, what is the final temperature of the gas? When an ideal gas does positive work on its surroundings, which of the gas’s quantities increases? How many particles of an ideal gas are in a cylinder with diameter and height of 100 nanometers pressurized to 1 Pa at a temperature of 1 K?

Problems to Solve: Heat Transfer How much energy is transferred through a circular glass window 0.45 m in diameter and 3.0 cm thick on a 10-hour long winter’s night where the temperature outside is -23oC and the temperature inside is 21oC? (kglass=0.96 W/mK; 1 kWh = 3,600,000 J) Holding all else constant, doubling the length and width of a window has what effect on the rate of conductive heat transfer through the window? Consider Figure 14-5 on page 391. What value of latent heat is required to change the liquid water into steam? At what points on the figure does the substance undergo a phase change?

Problems to Solve: Thermodynamic Laws How is conservation of internal energy expressed for a system during an adiabatic process? To calculate the efficiency of a heat engine, which thermodynamic properties must be known? If the entropy of a system decreases, what conclusion can you make about the entropy change of the environment? Construct a PV diagram using the following data. Then find the work done for the cycle going from point A to B to C to D and back to A. PA = 420 kPa | VA = 0.14 m3 PB = 420 kPa | VB = 0.18 m3 PC = 420 kPa | VC = 0.24 m3 PD = 370 kPa | VD = 0.24 m3